1. Field of the Invention
The present invention relates to a scraping apparatus and method for scraping the interior of a fluid handling device, for example, for cleaning the interiors of the tubes of a heat exchanger.
2. Description of the Background
FIG. 1 shows a conventional shell and tube heat exchanger, which is one example of a fluid handling device in which the current invention is useful. It comprises a plurality of tubes 10, a shell 11, and inlet and outlet manifolds 12, 13. No special means are provided in the conventional heat exchanger for scraping the interior thereof. For example, it typically is necessary to separate the manifolds 12, 13 from the shell 11 in order to scrape the interiors of the tubes 10. During such scraping, the heat exchanger may not be used. Consequently, the system in which the heat exchanger is used experiences down time. Furthermore, when the tubes 10 are lengthy, it frequently is extremely difficult to scrape the central portions of the tubes.
Of course, in the absence of such scraping the efficiency of the heat transfer will diminish over time due to the build-up of foreign matter. Such problems are not limited to heat exchangers. For example, a process pipe in a factory, an exhaust pipe and the like all are subject to the build-up of foreign matter on the insides thereof, causing increased frictional resistance to the flow of fluid therein.